Surgical sutures and suture anchors are used to close or hold together various types of soft tissue, including but not limited to skin, blood vessels, and internal organ tissue. In many instances, such sutures as well as all-suture suture anchors are made of biocompatible materials such as but not limited to non-absorbable materials such as cellulose (cotton, linen), protein (silk), processed collagen, nylon, polyester, polypropylene, aromatic polyamides (“aramid”), polytetraflourethylene, steel, copper, silver, aluminum, various alloys and the like, including many proprietary polymers and composites, to bioabsorbable (or biodegradable or bioerodible) synthetic materials, such as polymers and copolymers of glycolic and lactic acid. In some instances, such sutures have been coated with materials that provide additional benefits including antimicrobial, tribological properties, further biocompatible properties, and as well as materials that have properties to promote tissue growth and repair, including biodegradable matrices of growth factor molecules.
These suture and coating combinations often do not satisfy their desired efficacy as coatings are either removed during insertion of coated sutures due to abrasive contact with neighboring tissue or are rapidly degraded and diffused into the body before the coating can exert significant beneficial effects at the target site. Supplying high concentrations of bioactive material to the target site is not an effective solution as such concentrations may negate the benefits and indeed could be harmful, and further are relatively costly.
Attempting to address these issues, complex suture designs have utilized a multifilament biodegradable porous core surrounded by a biodegradable braided or woven sheath in which a concentration of living cells are retained within interstices disposed between the filaments of the core. In such designs, the sheath inhibits migration of the living cells from the porous core.
These designs require a concentration of bioactive material such as living cells and therapeutic agents throughout the cores and thus cannot be used with standard sutures as cores. Accordingly, other methods of preparation are needed to provide biocompatibility and tissue growth promotion benefits to surgical sutures and anchors made of suture material.